BBC 6分钟英语 被酶吃掉的塑料垃圾

6 min English from BBC learning english dot com.

Hello. This is Minute English from BBC Learning English.

I'm Neil, and I'm Beth. Plastic pollution is a problem weve discussed before on Six Minute it's an environmental issue, which, like the growing amounts of plastic waste, isn't going away.

But now, micro particles of plastic have even been found.

Can you guess where? Beth Hmm, let me guess.

Uh. In our food inside dead animals at the North Pole, at the top of Mount Everest, although the other places you mentioned are true as well.

Plastic is a tough problem to fix.

But fortunately, scientists may now have found a solution.

In this program, will be hearing about chemical recycling, groundbreaking way of making old plastic new again.

And as usual, we'll be learning some useful new vocabulary as well.

But 1st, I have a question for you, beth.

Visit the country or seaside, and you'll soon see evidence of plastic waste.

According to the UN around 400 million tons of new plastic is produced every year, much of it going to waste.

It's hard to imagine what 400 million tons looks like.

So which of the following, if you placed on a set of scales, would weigh about the same?

Is it a all the people on earth, be all the cars on Earth, or see all the elephants on Earth?

Hmm. I think all the cars on Earth would weigh about 400 million tons.

OK, beth, we'll find out if that's the right answer later.

Globally, less than 10% of all plastic gets recycled.

Some gets incinerated or burnt, and about half of all plastic waste goes straight to landfill, meaning it's buried underground.

But as reporter for BBC World Service program, people fixing the world, william Cramer explained this only fixes part of the problem.

So there is a mechanical process where some plastics can be sort of melted down and remoulded into a new shape or a new form.

But not all plastics can go through that process at all.

And also it loses a little bit of quality every time you do that, so it will become slightly more brittle.

So it's actually more down cycling than recycling, but every time it goes through that process, it gets less useful.

Each time plastic is recycled, it gets more brittle, meaning it's easier to break or crack.

As a result, what we call recycling is actually down cycling, creating recycled products which are less valuable and of lower quality than the original waste product.

And that's where the new discovery fits in.

chemical recycling, uses enzymes, natural chemicals, which cause changes in other chemicals without being changed themselves.

Certain enzymes have evolved the ability to break down plastic into its basic building blocks and use that to make new plastic.

The problem is that very few enzymes exist which can break the chemical bonds in stronger plastics, like P-E-T, the plastic used in drinks bottles.

At least, that's what scientists used to think, until researcher Sintoy Suliman took a autumn walk in the park near her laboratory at the University of a Sacker, japan.

In a pile of rotting leaves, she discovered the microorganism Leaf branch compost Cutinase, or L-C-C, for short, since we mixed L-C-C with plastic and left it in her lab overnight.

She was surprised to return the next morning and find the plastic gone eaten by the enzyme.

The news spread, and soon scientists were predicting a major breakthrough.

As William Kromer reported for BBC World Service program, people fixing the world.

This discovery wasn't the end of the story, but the beginning.

L CC showed promise in breaking down P-T plastic, but it needed a lot more work to become stable and effective.

The l CC enzyme showed promise in breaking down even strong plastics.

If something shows promise, it has the potential to be successful in the future.

Since then, that promise has started to come true.

Scientists in France have used L-C-C to develop new enzymes, and by 2025, they plan to recycle 50000 tons of plastic waste annually, including strong plastics like P-E-T and nylon, which is used to make clothes.

But they're still work today. 50000 Turns sounds a lot, but not as much as the 400 million tons of plastic waste in your question, neil.

So what was the correct answer?

Right? I asked you what else would weigh about 400 million tons, the amount of new plastic we produce each year.

You guessed all the cars on Earth would weigh the same, which was the wrong answer, I'm afraid,

beth? In fact, it was all the people on Earth.

OK, let's recap the vocabulary we've learned in this program, starting with incinerate.

Another word for burn. Landfill is a method of dealing with rubbish by burying it in large holes in the ground.

The adjective brittle means easily broken or snapped down.

Cycling is recycling, but in such a way that the resulting product is less valuable or of lower quality than the original.

Enzymes are chemicals found in living cells, which cause changes in other chemicals to happen while not being changed themselves.

And finally, if something shows promise, it has a lot of potential for success in the future.

Once again, our 6 min are up, but remember to join us again next time here at 6 min English.

Good Bye for now. Bye. Six news English from BBC.

Learning English dot com.

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